Interestingly, I wish there were the opposite of a do-not-email list for this kind of thing. I think it might actually be somewhat fun to get actually relevant email from companies working on interesting products in an extremely targeted way.

Then companies could just go and grab a lead list from there, with some metadata, and if too many people report it as spam (you could use a private relay on the site, for example, like mailinator) you lose access. Good citizens stay. And charge a nominal fee to enforce the reputation system.

I'm sure this is one of those "congratulations you have reinvented system Z" problems

Unfortunately I don't think it's possible for companies not to abuse your information, unless it's like 1-2 people and they're independently wealthy and the business is really more like a personal hobby.

I don't know how many times I've been to something like a niche clothing retailer and they ask me to join their mailing list for a discount and I think hey why not, I should come back in 6 months or a year and see what's new, maybe they'll let me know about their Labor Day sale. And of course they immediately proceed to email me 5 times a DAY because maybe I'm ready to shop now, when I wasn't at 2:00 pm. Unsubscribing only solves 20% of the problem because of course they subscribed me to 5 different daily lists and you need to unsubscribe separately. And, of course, if you don't do it quickly enough it will be 6, 7, 8, 10, 20 lists.

They're not human. They really can't help it.

You are basically just describing targeted advertising and it's already working like that, just not by email and probably more accurately than people putting themselves into buckets.

System Z is vaguely the read reply cards you would find in magazines. While I enjoyed the snail mail spammed materials, my parents were terrorized through the entire 90s by my abuse of those found in professional magazines like Computer Language.